# CVE-2021-31578: Memory corruption in EN7528, EN7580

> A stack buffer overflow in MediaTek Boa allows remote attackers to escalate privileges without user interaction or additional execution rights.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Feb 2023
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-g6j9-m726-789h

## What is CVE-2021-31578?

CVE-2021-31578 is a critical memory corruption vulnerability in MediaTek, Inc. EN7528, EN7580, published on 6 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Boa, there is a possible escalation of privilege due to a stack buffer overflow. This could lead to remote escalation of privilege from a proximal attacker with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: A20210008; Issue ID: OSBNB00123241.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-31578?

It affects 2 products.


Products: Mediatek En7528 Firmware, Mediatek En7580 Firmware.

## How do I fix CVE-2021-31578?

No fix has been published for CVE-2021-31578 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31578 being exploited?

There is no known exploitation of CVE-2021-31578 in the wild and no public exploit code.

## Other vulnerabilities in MediaTek, Inc. EN7528, EN7580

- [CVE-2021-31573](https://insights.sbomify.com/CVE-2021-31573/): Command injection in EN7528, EN7580 (critical 9.8)
- [CVE-2021-31574](https://insights.sbomify.com/CVE-2021-31574/): Command injection in EN7528, EN7580 (critical 9.8)
- [CVE-2021-31575](https://insights.sbomify.com/CVE-2021-31575/): Command injection in EN7528, EN7580 (critical 9.8)
- [CVE-2021-31577](https://insights.sbomify.com/CVE-2021-31577/): Missing authorization in EN7528, EN7580 (critical 9.8)
- [CVE-2021-31576](https://insights.sbomify.com/CVE-2021-31576/): Missing authorization in EN7528, EN7580 (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31578 and fix it if it is affected.

What it is: CVE-2021-31578 is a critical memory corruption vulnerability in MediaTek, Inc. EN7528, EN7580, published on 6 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-31578 in the wild and no public exploit code.

Affected product: MediaTek, Inc. EN7528, EN7580. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-31578/ (Markdown: https://insights.sbomify.com/CVE-2021-31578/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31578
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31578
- OSV: https://osv.dev/vulnerability/CVE-2021-31578

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31578/
Summaries are generated and may contain mistakes; the official description above is the record.